Electrostatics
Electrostatic Precipitators
So what's an Electrostatic Precipitator?
How is Electrostatics involved?
One of the major problems of this machine is how to extract the collected dust particles from the collection plates without them re-entering the airstream of purified gas. This is accomplished by rapper (metal hammers) that deliver vertical shock waves every so often that causes the dust particles to be sheared off into the collection containers and away from the newly cleaned air.
Basic Principles
Migration - transporting the charged particles to the collecting surfaces
Collection - accumulation of the charged particles onto the collecting surfaces
Charge Dissipation or Discharge - neutralizing the charged particles on the collection surfaces
Particle Dislodging- getting rid of the particles from the collection surfaces into the hopper bins
Particle Removal - transporting the particles from the hoppers to a disposal point
(a) Schematic of an electrostatic precipitator. Air is passed through grids of opposite charge. The first grid charges airborne particles, while the second attracts and collects them. (b) The dramatic effect of electrostatic precipitators is seen by the absence of smoke from this power plant. (Credit: Cmdalgleish, Wikimedia Commons) (resource: http://cnx.org/content/m42329/latest/?collection=col11406/latest)
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Works Cited
U.S. Environmental Protection Agency. Particulates - Electrostatic Precipitators. U.S. Environmental Protection Agency, January 29th, 2010. Website. February 10th, 2013.
http://www.epa.gov/eogapti1/course422/ce6a1.html
Blake, Leesa; Mazza, Michael; Mills, Alex; Mustoe, Frank; Ross, Jim; Stiff, Thomas. ON Science 9. Toronto: McGraw-Hill Ryerson Limited, 2009. Print.
Hoffman, Matt. “Choosing the Right Technology for Clean Indoor Air”. Occupational Hazards. 05-01-2004.
OSC Physics Maintainer. Connexions. Rice University, July 5th 2012. Web. February 20th, 2013.
Neundofer, Inc. Neundofer: Particulate Knowledge. Neundofer, Inc., n.d. Web. February 20th, 2013.
Braza, Rolando. "What Is an Electrostatic Precipitator?" WiseGeek. Ed. C. Wilborn. Conjecture, 04 Feb. 2013. Web. 20 Feb. 2013.
http://www.wisegeek.com/what-is-an-electrostatic-precipitator.htm